The Big Dipper with an old lens

 The Sigma 30mm f/1.4 EX DC HSM lens was one of the first fast autofocus prime lenses available for the Four-Thirds DSLR system.  My copy was purchased in 2007 for use with an Olympus E-500.  It can be used with current micro-four-thirds cameras via an adapter.  Tonight I used it with the Olympus MMF-1 adapter on an Olympus E-M1iii camera.

At this time of year in the late evening the Big Dipper is high in the sky.  This asterism is perfectly framed by the 30mm focal length. The lens was used wide open at f/1.4 with Hoya Softon and Sparkle-6 filters.  Sky brightness was measured as 19.80 mpsas, which is pretty good for this part of Santa Fe.  Recent rainy weather must have cleared the air.

softon filter

sparkle-6 filter

The results look pretty good at this size (2.3 Mpix via 3x binning), but there is very obvious astigmatism in the corners when viewed at higher resolution.  

A Starlink satellite train rose up through the sky (moving NW to SE) while I was out taking these pictures.  I wasn't prepared for that type of photography, so I just stood there and enjoyed the visual spectacle.  

Apogean Flower Moon

 The first Full Moon of May, traditionally called the "Flower Moon", was yesterday, 01 May.  This year there is a second full moon on 31 May.  The moon is approaching apogee (farthest from Earth) on 05 May, so this full moon is very close to being an Apogean Full Moon, colloquially known as a "micromoon".

Yesterday was a rainy day, and there was only a brief thinning of the clouds around 11 pm, when this image was taken.  The telescope was an Astro-Tech AT72EDII f/6 refractor.

 

01 May Flower Moon

The next morning I used the same equipment to photograph the sun (with a front-mounted solar filter):

02 May Sun

 The relative size of the apogean moon can be seen in a same-scale overlay of the sun and moon images:

 

Late-April Sun and Moon

 The 11.5-day moon was shining through a thin cloud layer last night.  I used the Sightron infini D50 refractor (50-mm aperture, 540-mm focal length) to capture an image.  A 1.5x MDB (Magic Dakin Barlow) was attached as a nosepiece to the E-M5iii camera.  This combination gives a final focal length of about 910 mm (1.68 magnification).

27 April

 

Lunar-photography setup

This morning I used the same camera and Barlow with a Lunt Solar Wedge to photograph the sun.

28 April

 

Solar-photography setup

camera and Barlow

The Moon and Venus

 During twilight on Saturday evening (18 April) the 1.7-day crescent moon passed within 5.5 deg of the planet Venus.  The conjunction was photographed with a Sony A7iii camera and Olympus OM 135mm f/2.8 lens, and an Olympus E-M1iii camera and 75mm f/1.8 lens.  Both cameras were hand held.

 

E-M1iii + 75mm f/1.8

About 1/2-hour later:

Sony A7iii + OM 135mm f/2.8

 

OM 135mm (left), Olympus 75mm (right)

A nearby star cluster and two nearby stars

The centerpiece of the constellation Coma Berenices is the open star-cluster known as Melotte 111, or the Coma Star Cluster.  At 280 ly distant , it is the second-closest recognizable open cluster, after the Hyades cluster.

The following images were obtained with a Sony A7iii camera and an Olympus 135mm f/2.8 lens riding on an iOptron SmartEQ Pro+ mount.  The measured sky brightness was 19.77 mpsas (location: Santa Fe).

Melotte 111, the Coma Star Cluster.  

This image was obtained with a Hoya Sparkle-6 filter.  This filter is way too aggressive for a lens with this focal length (135 mm), but it really brings out the relative colors of the stars.  

Here is a finder chart showing the location of Melotte 111 (Coma Star Cluster) relative to other constellations in the evening sky (Big Dipper on the left, Leo on the right):

credit: SkySafariAstronomy.com

This finder chart also hilights three nearby stars: Lalande 21185, Wolf 359, and Ross 128.

Lalande 21185 is the fourth closest star system after the Alpha Centauri system, Barnard's Star, and Wolf 359.  It is 8.3 ly distant.

Lalande 21185 (circled), the fourth closest star system.

 

Ross 128 is the 11th closest star system, at 11.0 ly, and magnitude 11.1 (triple 11's!).

Ross 128 (circled), the 11th closest star system.

 Here is a picture of the camera and lens attached to the IOptron mount:

 

 

 

Comet C/2025 R3 (PANSTARRS) from Santa Fe

 Comet C/2025 R3 (PANSTARRS) is visible low in the east at the beginning of astronomical dawn (about 5 am MDT).   The name derives from the Panoramic Survey Telescope And Rapid Response Sytem observatory in Hawaii  Between the neighborhood rooftops, trees, and power lines, getting a clear view is a challenge from my location in Santa Fe.  The comet is currently about magnitude 4.5 and is visible with binoculars.  I could easily see the head but not the tail with a 6x30 binocular.

The following images were obtained with an Olympus E-M1iii camera and 75mm f/1.8 lens.

  

current location in the dawn sky.  credit: SkySafariAstronomy.com

Venus setting

 Venus, at magnitude -3.9, is currently brighter than Jupiter (-2.2) and Sirius (-1.4).  From my location, Venus sets behind the Bristol Head ridgeline around 8:10 pm MDT.

Venus setting

 This image was obtained with an Olympus E-P5 camera and a Canon FD 300mm f/4L lens with a Metabones 0.71x Speed Booster.